Vlan Types - HP 3100 Series Configuration Manual

In the header of a traditional Ethernet data frame, the field after the destination MAC address and the
source MAC address is the Type field, which indicates the upper layer protocol type, as shown
in Figure 33.
Figure 33 Traditional Ethernet frame format
IEEE 802.1Q inserts a four-byte VLAN tag after the DA&SA field, as shown in
Figure 34 Position and format of VLAN tag
The fields of a VLAN tag are as follows:
•
TPID—The 16-bit TPID field indicates whether a frame is VLAN-tagged. By default, the TPID
value is 0x8100, which indicates that the frame is VLAN-tagged. Devices vendors can set the
TPID to different values. For compatibility with these devices, modify the TPID value so that
frames carry a TPID value identical to the value of a particular vendor, allowing interoperability
with devices from that vendor. The device determines whether a received frame carries a VLAN
tag by checking the TPID value. When the TPID value of a frame is the configured value or
0x8100, the frame is considered as a VLAN-tagged frame. For information about commands
used to modify TPID values, see Layer 2—LAN Switching Command Reference.
•
Priority—The 3-bit priority field indicates the 802.1p priority of the frame.
•
CFI—The 1-bit CFI field indicates whether the MAC addresses are encapsulated in standard
format when packets are transmitted across different media. A value of 0 indicates that MAC
addresses are encapsulated in standard format. A value of 1 indicates that MAC addresses are
encapsulated in a non-standard format. The value of this field is 0 by default.
•
VLAN ID—The 12-bit VLAN ID field identifies the VLAN that the frame belongs to. The VLAN ID
range is 0 to 4095. Because 0 and 4095 are reserved, a VLAN ID actually ranges from 1 to
4094.
A network device handles an incoming frame depending on whether the frame is VLAN tagged, and
information about the VLAN tags, if any. For more information, see
VLAN."
NOTE:
When a frame carrying multiple VLAN tags passes through, the switch processes the frame
according to its outer VLAN tag, and transmits the inner tags as payload.

VLAN types

You can implement VLANs based on the following criteria:
•
Port
•
MAC address
•
Protocol
•
IP subnet
•
Policy
•
Other criteria
When you configure VLANs on an HPE 3100 v2 switch, follow these guidelines:
105
Figure 34.
"Introduction to port-based